Weather and Traffic

South Florida on track for unusually warm December

With almost half the month in the record books, Palm Beach appears to be on track for an unusally toasty December. Temperatures have been averaging almost 4 degrees above normal (taking into consideration the high and the low).

We’ve had only two days when the temperature was below average — Dec. 1, when we had a chilly low of 51 degrees, and Dec. 8, with a low of 58.

On the other hand, we’ve had five days of 80 degrees or better and another three that came in at 79.

Compare that, if you will, to 2010 when every day in the first half of the month was well below average. In fact, all but the final two days of the month were in negative territory.

The extended forecast is for more of the same through the end of the month. AccuWeather, however, is predicting a rainy Christmas week beginning Christmas Eve and continuing through most of the following week.

The warmest December on record, according to the Southeast Regional Climate Center, was 2006, when the daily average came in at 73.15 degrees. As of Thursday, the average monthly temperature at Palm Beach International Airport was 73.3 degrees and there are no serious cold fronts — so far — on the horizon.

I found it interesting that, accompanying our December warm spell, sea surface temperatures (SSTs) surrounding the Florida peninsula have plummeted over the last two months. The state is now surrounded by water that is well below the historical average for this time of the year.

Here are two graphics from the National Oceanic and Atmospheric Administration’s Satellite and Information Service. The first shows SST anomalies as of Thursday. The second shows what they looked like in early October. (Remember that these are anomalies and not actual temperatures.)

From year to year, SST anomalies fluctuate off-shore of the peninsula in the Atlantic and Gulf of Mexico. The graphic below shows what the situation looked like in December 2009. We were surrounded by relatively warm water, but winter temperatures in South Florida that year were on the cool side.

On the other hand, during the 2010-2011 winter, December SSTs surrounding Florida were cold. But we ended up with average temperatures in South Florida in January, followed by a very balmy February.